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1.
Mol Cell ; 83(20): 3582-3587, 2023 10 19.
Article in English | MEDLINE | ID: mdl-37863025

ABSTRACT

In recent years, increasing evidence has highlighted the profound connection between DNA damage repair and the activation of immune responses. We spoke with researchers about their mechanistic interplays and the implications for cancer and other diseases.


Subject(s)
DNA Damage , DNA Repair , Signal Transduction , Immunity
2.
Cell ; 153(3): 590-600, 2013 Apr 25.
Article in English | MEDLINE | ID: mdl-23622243

ABSTRACT

DNA mismatch repair (MMR) ensures replication fidelity by correcting mismatches generated during DNA replication. Although human MMR has been reconstituted in vitro, how MMR occurs in vivo is unknown. Here, we show that an epigenetic histone mark, H3K36me3, is required in vivo to recruit the mismatch recognition protein hMutSα (hMSH2-hMSH6) onto chromatin through direct interactions with the hMSH6 PWWP domain. The abundance of H3K36me3 in G1 and early S phases ensures that hMutSα is enriched on chromatin before mispairs are introduced during DNA replication. Cells lacking the H3K36 trimethyltransferase SETD2 display microsatellite instability (MSI) and an elevated spontaneous mutation frequency, characteristic of MMR-deficient cells. This work reveals that a histone mark regulates MMR in human cells and explains the long-standing puzzle of MSI-positive cancer cells that lack detectable mutations in known MMR genes.


Subject(s)
DNA Mismatch Repair , DNA-Binding Proteins/metabolism , Histone Code , Amino Acid Sequence , Chromatin/metabolism , DNA-Binding Proteins/chemistry , Humans , Methylation , Models, Molecular , Molecular Sequence Data , Protein Structure, Tertiary , Sequence Alignment
3.
Cell ; 153(5): 1012-24, 2013 May 23.
Article in English | MEDLINE | ID: mdl-23706739

ABSTRACT

Histone acetylation plays critical roles in chromatin remodeling, DNA repair, and epigenetic regulation of gene expression, but the underlying mechanisms are unclear. Proteasomes usually catalyze ATP- and polyubiquitin-dependent proteolysis. Here, we show that the proteasomes containing the activator PA200 catalyze the polyubiquitin-independent degradation of histones. Most proteasomes in mammalian testes ("spermatoproteasomes") contain a spermatid/sperm-specific α subunit α4 s/PSMA8 and/or the catalytic ß subunits of immunoproteasomes in addition to PA200. Deletion of PA200 in mice abolishes acetylation-dependent degradation of somatic core histones during DNA double-strand breaks and delays core histone disappearance in elongated spermatids. Purified PA200 greatly promotes ATP-independent proteasomal degradation of the acetylated core histones, but not polyubiquitinated proteins. Furthermore, acetylation on histones is required for their binding to the bromodomain-like regions in PA200 and its yeast ortholog, Blm10. Thus, PA200/Blm10 specifically targets the core histones for acetylation-mediated degradation by proteasomes, providing mechanisms by which acetylation regulates histone degradation, DNA repair, and spermatogenesis.


Subject(s)
DNA Repair , Histones/metabolism , Nuclear Proteins/metabolism , Proteasome Endopeptidase Complex/metabolism , Spermatogenesis , Testis/metabolism , Acetylation , Amino Acid Sequence , Animals , DNA Breaks, Double-Stranded , Humans , Male , Mice , Molecular Sequence Data , Nuclear Proteins/chemistry , Protein Structure, Tertiary , Saccharomyces cerevisiae/metabolism , Saccharomyces cerevisiae Proteins/metabolism , Sequence Alignment
4.
Plant Cell ; 36(5): 2000-2020, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38299379

ABSTRACT

The flower-infecting fungus Ustilaginoidea virens causes rice false smut, which is a severe emerging disease threatening rice (Oryza sativa) production worldwide. False smut not only reduces yield, but more importantly produces toxins on grains, posing a great threat to food safety. U. virens invades spikelets via the gap between the 2 bracts (lemma and palea) enclosing the floret and specifically infects the stamen and pistil. Molecular mechanisms for the U. virens-rice interaction are largely unknown. Here, we demonstrate that rice flowers predominantly employ chitin-triggered immunity against U. virens in the lemma and palea, rather than in the stamen and pistil. We identify a crucial U. virens virulence factor, named UvGH18.1, which carries glycoside hydrolase activity. Mechanistically, UvGH18.1 functions by binding to and hydrolyzing immune elicitor chitin and interacting with the chitin receptor CHITIN ELICITOR BINDING PROTEIN (OsCEBiP) and co-receptor CHITIN ELICITOR RECEPTOR KINASE1 (OsCERK1) to impair their chitin-induced dimerization, suppressing host immunity exerted at the lemma and palea for gaining access to the stamen and pistil. Conversely, pretreatment on spikelets with chitin induces a defense response in the lemma and palea, promoting resistance against U. virens. Collectively, our data uncover a mechanism for a U. virens virulence factor and the critical location of the host-pathogen interaction in flowers and provide a potential strategy to control rice false smut disease.


Subject(s)
Chitin , Flowers , Hypocreales , Oryza , Plant Diseases , Oryza/microbiology , Oryza/metabolism , Oryza/genetics , Plant Diseases/microbiology , Chitin/metabolism , Flowers/microbiology , Hypocreales/pathogenicity , Hypocreales/genetics , Hypocreales/metabolism , Signal Transduction , Host-Pathogen Interactions , Plant Proteins/metabolism , Plant Proteins/genetics , Virulence , Virulence Factors/metabolism , Virulence Factors/genetics , Fungal Proteins/metabolism , Fungal Proteins/genetics
5.
Proc Natl Acad Sci U S A ; 121(13): e2313652121, 2024 Mar 26.
Article in English | MEDLINE | ID: mdl-38498709

ABSTRACT

Huntington's disease (HD) is an inherited neurodegenerative disorder caused by an expanded CAG repeat in the huntingtin (HTT) gene. The repeat-expanded HTT encodes a mutated HTT (mHTT), which is known to induce DNA double-strand breaks (DSBs), activation of the cGAS-STING pathway, and apoptosis in HD. However, the mechanism by which mHTT triggers these events is unknown. Here, we show that HTT interacts with both exonuclease 1 (Exo1) and MutLα (MLH1-PMS2), a negative regulator of Exo1. While the HTT-Exo1 interaction suppresses the Exo1-catalyzed DNA end resection during DSB repair, the HTT-MutLα interaction functions to stabilize MLH1. However, mHTT displays a significantly reduced interaction with Exo1 or MutLα, thereby losing the ability to regulate Exo1. Thus, cells expressing mHTT exhibit rapid MLH1 degradation and hyperactive DNA excision, which causes severe DNA damage and cytosolic DNA accumulation. This activates the cGAS-STING pathway to mediate apoptosis. Therefore, we have identified unique functions for both HTT and mHTT in modulating DNA repair and the cGAS-STING pathway-mediated apoptosis by interacting with MLH1. Our work elucidates the mechanism by which mHTT causes HD.


Subject(s)
Huntington Disease , Humans , Huntingtin Protein/genetics , Huntingtin Protein/metabolism , Mutant Proteins/genetics , Huntington Disease/genetics , Huntington Disease/metabolism , Nucleotidyltransferases/genetics , DNA , Apoptosis/genetics , MutL Protein Homolog 1/genetics
6.
Proc Natl Acad Sci U S A ; 121(4): e2311732121, 2024 Jan 23.
Article in English | MEDLINE | ID: mdl-38232289

ABSTRACT

Rechargeable lithium (Li) metal batteries face challenges in achieving stable cycling due to the instability of the solid electrolyte interphase (SEI). The Li-ion solvation structure and its desolvation process are crucial for the formation of a stable SEI on Li metal anodes and improving Li plating/stripping kinetics. This research introduces an interfacial desolvation coating technique to actively modulate the Li-ion solvation structure at the Li metal interface and regulate the participation of the electrolyte solvent in SEI formation. Through experimental investigations conducted using a carbonate electrolyte with limited compatibility to Li metal, the optimized desolvation coating layer, composed of 12-crown-4 ether-modified silica materials, selectively displaces strongly coordinating solvents while simultaneously enriching weakly coordinating fluorinated solvents at the Li metal/electrolyte interface. This selective desolvation and enrichment effect reduce solvent participation to SEI and thus facilitate the formation of a LiF-dominant SEI with greatly reduced organic species on the Li metal surface, as conclusively verified through various characterization techniques including XPS, quantitative NMR, operando NMR, cryo-TEM, EELS, and EDS. The interfacial desolvation coating technique enables excellent rate cycling stability (i.e., 1C) of the Li metal anode and prolonged cycling life of the Li||LiCoO2 pouch cell in the conventional carbonate electrolyte (E/C 2.6 g/Ah), with 80% capacity retention after 333 cycles.

7.
PLoS Pathog ; 20(4): e1012123, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38607975

ABSTRACT

RAB GTPases (RABs) control intracellular membrane trafficking with high precision. In the present study, we carried out a short hairpin RNA (shRNA) screen focused on a library of 62 RABs during infection with porcine reproductive and respiratory syndrome virus 2 (PRRSV-2), a member of the family Arteriviridae. We found that 13 RABs negatively affect the yield of PRRSV-2 progeny virus, whereas 29 RABs have a positive impact on the yield of PRRSV-2 progeny virus. Further analysis revealed that PRRSV-2 infection transcriptionally regulated RAB18 through RIG-I/MAVS-mediated canonical NF-κB activation. Disrupting RAB18 expression led to the accumulation of lipid droplets (LDs), impaired LDs catabolism, and flawed viral replication and assembly. We also discovered that PRRSV-2 co-opts chaperone-mediated autophagy (CMA) for lipolysis via RAB18, as indicated by the enhanced associations between RAB18 and perlipin 2 (PLIN2), CMA-specific lysosomal associated membrane protein 2A (LAMP2A), and heat shock protein family A (Hsp70) member 8 (HSPA8/HSC70) during PRRSV-2 infection. Knockdown of HSPA8 and LAMP2A impacted on the yield of PRRSV-2 progeny virus, implying that the virus utilizes RAB18 to promote CMA-mediated lipolysis. Importantly, we determined that the C-terminal domain (CTD) of HSPA8 could bind to the switch II domain of RAB18, and the CTD of PLIN2 was capable of associating with HSPA8, suggesting that HSPA8 facilitates the interaction between RAB18 and PLIN2 in the CMA process. In summary, our findings elucidate how PRRSV-2 hijacks CMA-mediated lipid metabolism through innate immune activation to enhance the yield of progeny virus, offering novel insights for the development of anti-PRRSV-2 treatments.


Subject(s)
Chaperone-Mediated Autophagy , Porcine respiratory and reproductive syndrome virus , Swine , Animals , Lipolysis , Up-Regulation , rab GTP-Binding Proteins/genetics , Lysosomal Membrane Proteins , RNA, Small Interfering
8.
Nat Chem Biol ; 2024 Sep 19.
Article in English | MEDLINE | ID: mdl-39300230

ABSTRACT

Clustered regularly interspaced short palindromic repeats-Cas13 effectors are used for RNA editing but the adeno-associated virus (AAV) packaging limitations because of their big sizes hinder their therapeutic application. Here we report the identification of the Cas13j family, with LepCas13j (529 aa) and ChiCas13j (424 aa) being the smallest and most highly efficient variants for RNA interference. The miniaturized Cas13j proteins enable the development of compact RNA base editors. Chi-RESCUE-S, by fusing dChiCas13j with hADAR2dd, demonstrates high efficiency and specificity in A-to-G and C-to-U conversions. Importantly, this system is compatible with single-AAV packaging without the need for protein sequence truncation. It successfully corrected pathogenic mutations, such as APOC3D65N and SCN9AR896Q, to the wild-type forms. In addition, we developed an optimized system, Chi-RESCUE-S-mini3, which pioneered efficient in vivo C-to-U RNA editing of PCSK9 in mice through single-AAV delivery, resulting in reduced total cholesterol levels. These results highlight the potential of Cas13j to treat human diseases.

9.
PLoS Biol ; 21(7): e3002197, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37410725

ABSTRACT

Drosophila melanogaster Down syndrome cell adhesion molecule 1 (Dscam1) encodes 19,008 diverse ectodomain isoforms via the alternative splicing of exon 4, 6, and 9 clusters. However, whether individual isoforms or exon clusters have specific significance is unclear. Here, using phenotype-diversity correlation analysis, we reveal the redundant and specific roles of Dscam1 diversity in neuronal wiring. A series of deletion mutations were performed from the endogenous locus harboring exon 4, 6, or 9 clusters, reducing to 396 to 18,612 potential ectodomain isoforms. Of the 3 types of neurons assessed, dendrite self/non-self discrimination required a minimum number of isoforms (approximately 2,000), independent of exon clusters or isoforms. In contrast, normal axon patterning in the mushroom body and mechanosensory neurons requires many more isoforms that tend to associate with specific exon clusters or isoforms. We conclude that the role of the Dscam1 diversity in dendrite self/non-self discrimination is nonspecifically mediated by its isoform diversity. In contrast, a separate role requires variable domain- or isoform-related functions and is essential for other neurodevelopmental contexts, such as axonal growth and branching. Our findings shed new light on a general principle for the role of Dscam1 diversity in neuronal wiring.


Subject(s)
Down Syndrome , Drosophila Proteins , Animals , Drosophila melanogaster/metabolism , Drosophila Proteins/genetics , Drosophila Proteins/metabolism , Cell Adhesion Molecule-1/genetics , Cell Adhesion Molecule-1/metabolism , Cell Adhesion Molecules/genetics , Cell Adhesion Molecules/metabolism , Clustered Regularly Interspaced Short Palindromic Repeats , Down Syndrome/genetics , Protein Isoforms/genetics , Protein Isoforms/metabolism , Neurons/metabolism
10.
Nucleic Acids Res ; 52(5): 2142-2156, 2024 Mar 21.
Article in English | MEDLINE | ID: mdl-38340342

ABSTRACT

Human DNA topoisomerase 1 (Top1) is a crucial enzyme responsible for alleviating torsional stress on DNA during transcription and replication, thereby maintaining genome stability. Previous researches had found that non-working Top1 interacted extensively with chromosomal DNA in human cells. However, the reason for its retention on chromosomal DNA remained unclear. In this study, we discovered a close association between Top1 and chromosomal DNA, specifically linked to the presence of G-quadruplex (G4) structures. G4 structures, formed during transcription, trap Top1 and hinder its ability to relax neighboring DNAs. Disruption of the Top1-G4 interaction using G4 ligand relieved the inhibitory effect of G4 on Top1 activity, resulting in a further reduction of R-loop levels in cells. Additionally, the activation of Top1 through the use of a G4 ligand enhanced the toxicity of Top1 inhibitors towards cancer cells. Our study uncovers a negative regulation mechanism of human Top1 and highlights a novel pathway for activating Top1.


Subject(s)
DNA Topoisomerases, Type I , G-Quadruplexes , Transcription, Genetic , Humans , DNA/chemistry , DNA Replication , DNA Topoisomerases, Type I/metabolism , Ligands , Topoisomerase I Inhibitors/pharmacology
11.
Bioinformatics ; 2024 Oct 11.
Article in English | MEDLINE | ID: mdl-39392404

ABSTRACT

MOTIVATION: Target discovery is a crucial step in drug development, as it directly affects the success rate of clinical trials. Knowledge graphs (KGs) offer unique advantages in processing complex biological data and inferring new relationships. Existing biomedical KGs primarily focus on tasks such as drug repositioning and drug-target interactions, leaving a gap in the construction of KGs tailored for target discovery. RESULTS: We established a comprehensive biomedical KG focusing on target discovery, termed TarKG, by integrating seven existing biomedical KGs, nine public databases, and traditional Chinese medicine knowledge databases. TarKG consists of 1,143,313 entities and 32,806,467 relations across 15 entity categories and 171 relation types, all centered around three core entity types: Disease, Gene, Compound. TarKG provides specialized knowledges for the core entities including chemical structures, protein sequences or text descriptions. By using different KG embedding algorithms, we assessed the knowledge completion capabilities of TarKG, particularly for disease-target link prediction. In case studies, we further examined TarKG's ability to predict potential protein targets for Alzheimer's disease (AD) and to identify diseases potentially associated with the metallo-deubiquitinase CSN5, using literature analysis for validation. Furthermore, we provided a user-friendly web server (https://tarkg.ddtmlab.org) that enables users to perform knowledge retrieval and relation inference using TarKG. AVAILABILITY: TarKG is accessible at https://tarkg.ddtmlab.org. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

12.
PLoS Pathog ; 19(6): e1011482, 2023 06.
Article in English | MEDLINE | ID: mdl-37379353

ABSTRACT

Wall teichoic acid (WTA) is the abundant cell wall-associated glycopolymer in Gram-positive bacteria, playing crucial roles in surface proteins retention, bacterial homeostasis, and virulence. The WTA glycosylation of Listeria monocytogenes is essential for surface anchoring of virulence factors, whereas the nature and function of the noncovalent interactions between cell wall-associated proteins and WTA are less unknown. In this study, we found that galactosylated WTA (Gal-WTA) of serovar (SV) 4h L. monocytogenes plays a key role in modulating the novel glycine-tryptophan (GW) domain-containing autolysin protein LygA through direct interactions. Gal-deficient WTA of Lm XYSN (ΔgalT) showed a dramatic reduction of LygA on the cell surface. We demonstrated that LygA binds to Gal-WTA through the GW domains, and the binding affinity is associated with the number of GW motifs. Moreover, we confirmed the direct Gal-dependent binding of the GW protein Auto from the type I WTA strain, which has no interaction with rhamnosylated WTA, indicating that the complexity of both WTA and GW proteins affect the coordination patterns. Importantly, we revealed the crucial roles of LygA in facilitating bacterial homeostasis as well as crossing the intestinal and blood-brain barriers. Altogether, our findings suggest that both the glycosylation patterns of WTA and a fixed numbers of GW domains are closely associated with the retention of LygA on the cell surface, which promotes the pathogenesis of L. monocytogenes within the host.


Subject(s)
Listeria monocytogenes , Virulence , Cell Membrane/metabolism , Cell Wall/metabolism , Virulence Factors/metabolism , Membrane Proteins/metabolism , Teichoic Acids/metabolism , Bacterial Proteins/metabolism
13.
Stem Cells ; 2024 Sep 16.
Article in English | MEDLINE | ID: mdl-39283950

ABSTRACT

CRISPR-Cas9 editing triggers activation of the TP53-p21 pathway, but the impacts of different editing components and delivery methods have not been fully explored. In this study, we introduce a p21-mNeonGreen reporter iPSC line to monitor TP53-p21 pathway activation. This reporter enables dynamic tracking of p21 expression via flow cytometry, revealing a strong correlation between p21 expression and indel frequencies, and highlighting its utility in guide RNA screening. Our findings show that p21 activation is significantly more pronounced with double-stranded oligodeoxynucleotides (ODNs) or adeno-associated viral vectors (AAVs) compared to their single-stranded counterparts. Lentiviral vectors (LVs) and integrase-defective lentiviral vectors (IDLVs) induce notably lower p21 expression than AAVs, suggesting their suitability for gene therapy in sensitive cells such as hematopoietic stem cells or immune cells. Additionally, specific viral promoters like SFFV significantly amplify p21 activation, emphasizing the critical role of promoter selection in vector development. Thus, the p21-mNeonGreen reporter iPSC line is a valuable tool for assessing the potential adverse effects of gene editing methodologies and vectors.

14.
EMBO Rep ; 24(2): e54313, 2023 02 06.
Article in English | MEDLINE | ID: mdl-36524339

ABSTRACT

Somatosensory neurons are highly heterogeneous with distinct types of neural cells responding to specific stimuli. However, the distribution and roles of cell-type-specific long intergenic noncoding RNAs (lincRNAs) in somatosensory neurons remain largely unexplored. Here, by utilizing droplet-based single-cell RNA-seq (scRNA-seq) and full-length Smart-seq2, we show that lincRNAs, but not coding mRNAs, are enriched in specific types of mouse somatosensory neurons. Profiling of lincRNAs from single neurons located in dorsal root ganglia (DRG) identifies 200 lincRNAs localized in specific types or subtypes of somatosensory neurons. Among them, the conserved cell-type-specific lincRNA CLAP associates with pruritus and is abundantly expressed in somatostatin (SST)-positive neurons. CLAP knockdown reduces histamine-induced Ca2+ influx in cultured SST-positive neurons and in vivo reduces histamine-induced scratching in mice. In vivo knockdown of CLAP also decreases the expression of neuron-type-specific and itch-related genes in somatosensory neurons, and this partially depends on the RNA binding protein MSI2. Our data reveal a cell-type-specific landscape of lincRNAs and a function for CLAP in somatosensory neurons in sensory transmission.


Subject(s)
Pruritus , RNA, Long Noncoding , Sensory Receptor Cells , Animals , Mice , Histamine , Pruritus/genetics , RNA, Long Noncoding/genetics , Sensation
15.
Nucleic Acids Res ; 51(D1): D593-D602, 2023 01 06.
Article in English | MEDLINE | ID: mdl-36243971

ABSTRACT

Metalloenzymes are attractive research targets in fields of chemistry, biology, and medicine. Given that metalloenzymes can manifest conservation of metal-coordination and ligand binding modes, the excavation and expansion of metalloenzyme-specific knowledge is of interest in bridging metalloenzyme-related fields. Building on our previous metalloenzyme-ligand association database, MeLAD, we have expanded the scope of metalloenzyme-specific knowledge and services, by forming a versatile platform, termed the Metalloenzyme Data Bank and Analysis (MeDBA). The MeDBA provides: (i) manual curation of metalloenzymes into different categories, that this M-I, M-II and M-III; (ii) comprehensive information on metalloenzyme activities, expression profiles, family and disease links; (iii) structural information on metalloenzymes, in particular metal binding modes; (iv) metalloenzyme substrates and bioactive molecules acting on metalloenzymes; (v) excavated metal-binding pharmacophores and (vi) analysis tools for structure/metal active site comparison and metalloenzyme profiling. The MeDBA is freely available at https://medba.ddtmlab.org.


Subject(s)
Databases, Protein , Metalloproteins , Catalytic Domain , Ligands , Metalloproteins/metabolism , Metals , Enzymes
16.
PLoS Genet ; 18(10): e1010455, 2022 10.
Article in English | MEDLINE | ID: mdl-36206313

ABSTRACT

Many plant secondary substances are feeding deterrents for insects and play a key role in the selection of host plants. The taste sensilla of phytophagous insects contain gustatory sensory neurons sensitive to deterrents but the molecular basis of deterrent chemoreception remains unknown. We investigated the function of Gr180, the most highly expressed bitter gustatory receptor in the maxillary galea of Helicoverpa armigera larvae. Functional analyses using the Xenopus oocyte expression system and two-electrode voltage clamp revealed that the oocytes expressing Gr180 responded to coumarin. Tip recording results showed that the medial sensilla styloconica of the maxilla of fifth instar larvae exhibited electrophysiological responses to coumarin. Two-choice feeding bioassays confirmed that coumarin inhibited larval feeding. A homozygous mutant strain of H. armigera with truncated Gr180 proteins (Gr180-/-) was established using the CRISPR-Cas9 system. The responses of the medial sensilla styloconica in Gr180-/- to coumarin were almost abolished, and the responses to sinigrin and strychnine were also significantly decreased. Knockout of Gr180 alleviated the feeding deterrent effects of coumarin, sinigrin, and strychnine. Thus, we conclude that Gr180 is a receptor responding to coumarin,and also participates in sensing sinigrin and strychnine. These results enhance our understanding of the gustatory sensing mechanisms of phytophagous insects to deterrents.


Subject(s)
Moths , Taste , Animals , Larva/metabolism , Taste/genetics , Strychnine/metabolism , Strychnine/pharmacology , Maxilla/metabolism , Moths/genetics , Receptors, Cell Surface/genetics , Receptors, Cell Surface/metabolism , Coumarins/metabolism , Coumarins/pharmacology
17.
Proc Natl Acad Sci U S A ; 119(40): e2201738119, 2022 10 04.
Article in English | MEDLINE | ID: mdl-36161943

ABSTRACT

Mismatch repair (MMR) is a replication-coupled DNA repair mechanism and plays multiple roles at the replication fork. The well-established MMR functions include correcting misincorporated nucleotides that have escaped the proofreading activity of DNA polymerases, recognizing nonmismatched DNA adducts, and triggering a DNA damage response. In an attempt to determine whether MMR regulates replication progression in cells expressing an ultramutable DNA polymerase ɛ (Polɛ), carrying a proline-to-arginine substitution at amino acid 286 (Polɛ-P286R), we identified an unusual MMR function in response to hydroxyurea (HU)-induced replication stress. Polɛ-P286R cells treated with hydroxyurea exhibit increased MRE11-catalyzed nascent strand degradation. This degradation by MRE11 depends on the mismatch recognition protein MutSα and its binding to stalled replication forks. Increased MutSα binding at replication forks is also associated with decreased loading of replication fork protection factors FANCD2 and BRCA1, suggesting blockage of these fork protection factors from loading to replication forks by MutSα. We find that the MutSα-dependent MRE11-catalyzed fork degradation induces DNA breaks and various chromosome abnormalities. Therefore, unlike the well-known MMR functions of ensuring replication fidelity, the newly identified MMR activity of promoting genome instability may also play a role in cancer avoidance by eliminating rogue cells.


Subject(s)
DNA-Binding Proteins , Hydroxyurea , Amino Acids/genetics , Arginine/genetics , DNA Adducts , DNA Mismatch Repair , DNA Replication , DNA-Binding Proteins/metabolism , DNA-Directed DNA Polymerase/genetics , DNA-Directed DNA Polymerase/metabolism , Hydroxyurea/pharmacology , MRE11 Homologue Protein/genetics , MRE11 Homologue Protein/metabolism , Nucleotides/metabolism , Proline/genetics
18.
Proc Natl Acad Sci U S A ; 119(49): e2215442119, 2022 12 06.
Article in English | MEDLINE | ID: mdl-36442117

ABSTRACT

Sex pheromones are pivotal for insect reproduction. However, the mechanism of sex pheromone communication remains enigmatic in hymenopteran parasitoids. Here we have identified the sex pheromone and elucidated the olfactory basis of sex pheromone communication in Campoletis chlorideae (Ichneumonidae), a solitary larval endoparasitoid of over 30 lepidopteran pests. Using coupled gas chromatography-electroantennogram detection, we identified two female-derived pheromone components, tetradecanal (14:Ald) and 2-heptadecanone (2-Hep) (1:4.6), eliciting strong antennal responses from males but weak responses from females. We observed that males but not females were attracted to both single components and the blend. The hexane-washed female cadavers failed to arouse males, and replenishing 14:Ald and 2-Hep could partially restore the sexual attraction of males. We further expressed six C. chlorideae male-biased odorant receptors in Drosophila T1 neurons and found that CchlOR18 and CchlOR47 were selectively tuned to 14:Ald and 2-Hep, respectively. To verify the biological significance of this data, we knocked down CchlOR18 and CchlOR47 individually or together in vivo and show that the attraction of C. chlorideae to their respective ligands was abolished. Moreover, the parasitoids defective in either of the receptors were less likely to court and copulate. Finally, we show that the sex pheromone and (Z)-jasmone, a potent female attractant, can synergistically affect behaviors of virgin males and virgin females and ultimately increase the parasitic efficiency of C. chlorideae. Our study provides new insights into the molecular mechanism of sex pheromone communication in C. chlorideae that may permit manipulation of parasitoid behavior for pest control.


Subject(s)
Receptors, Odorant , Sex Attractants , Male , Animals , Insecta , Communication , Pheromones , Drosophila
19.
Genomics ; 116(5): 110889, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38901654

ABSTRACT

Cholangiocarcinoma (CCA) is widely noted for its high degree of malignancy, rapid progression, and limited therapeutic options. This study was carried out on transcriptome data of 417 CCA samples from different anatomical locations. The effects of lipid metabolism related genes and immune related genes as CCA classifiers were compared. Key genes were derived from MVI subtypes and better molecular subtypes. Pathways such as epithelial mesenchymal transition (EMT) and cell cycle were significantly activated in MVI-positive group. CCA patients were classified into three (four) subtypes based on lipid metabolism (immune) related genes, with better prognosis observed in lipid metabolism-C1, immune-C2, and immune-C4. IPTW analysis found that the prognosis of lipid metabolism-C1 was significantly better than that of lipid metabolism-C2 + C3 before and after correction. KRT16 was finally selected as the key gene. And knockdown of KRT16 inhibited proliferation, migration and invasion of CCA cells.


Subject(s)
Bile Duct Neoplasms , Biomarkers, Tumor , Cholangiocarcinoma , Epithelial-Mesenchymal Transition , Cholangiocarcinoma/genetics , Cholangiocarcinoma/metabolism , Cholangiocarcinoma/pathology , Humans , Bile Duct Neoplasms/genetics , Bile Duct Neoplasms/metabolism , Bile Duct Neoplasms/pathology , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Cell Line, Tumor , Prognosis , Male , Lipid Metabolism , Cell Movement , Female , Cell Proliferation , Transcriptome , Middle Aged , Gene Expression Regulation, Neoplastic
20.
BMC Genomics ; 25(1): 92, 2024 Jan 22.
Article in English | MEDLINE | ID: mdl-38254015

ABSTRACT

BACKGROUND: Gorals Naemorhedus resemble both goats and antelopes, which prompts much debate about the intragenus species delimitation and phylogenetic status of the genus Naemorhedus within the subfamily Caprinae. Their evolution is believed to be linked to the uplift of the Qinghai-Tibet Plateau (QTP). To better understand its phylogenetics, the genetic information is worth being resolved. RESULTS: Based on a sample from the eastern margin of QTP, we constructed the first reference genome for Himalayan goral Naemorhedus goral, using PacBio long-read sequencing and Hi-C technology. The 2.59 Gb assembled genome had a contig N50 of 3.70 Mb and scaffold N50 of 106.66 Mb, which anchored onto 28 pseudo chromosomes. A total of 20,145 protein-coding genes were predicted in the assembled genome, of which 99.93% were functionally annotated. Phylogenetically, the goral was closely related to muskox on the mitochondrial genome level and nested into the takin-muskox clade on the genome tree, rather than other so-called goat-antelopes. The cladogenetic event among muskox, takin and goral occurred sequentially during the late Miocene (~ 11 - 5 Mya), when the QTP experienced a third dramatic uplift with consequent profound changes in climate and environment. Several chromosome fusions and translocations were observed between goral and takin/muskox. The expanded gene families in the goral genome were mainly related to the metabolism of drugs and diseases, so as the positive selected genes. The Ne of goral continued to decrease since ~ 1 Mya during the Pleistocene with active glaciations. CONCLUSION: The high-quality goral genome provides insights into the evolution and valuable information for the conservation of this threatened group.


Subject(s)
Antelopes , Animals , Antelopes/genetics , Phylogeny , Goats/genetics , Gene Rearrangement , Chromosomes
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